蒙代尔的三元悖论或不可能三角英文是什么?如题如果能提供下这个理论的相关英文资料就更好啦!
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蒙代尔的三元悖论或不可能三角英文是什么?如题如果能提供下这个理论的相关英文资料就更好啦!
蒙代尔的三元悖论或不可能三角英文是什么?
如题
如果能提供下这个理论的相关英文资料就更好啦!
蒙代尔的三元悖论或不可能三角英文是什么?如题如果能提供下这个理论的相关英文资料就更好啦!
三元悖论,也称三难选择,它是由美国经济学家保罗·克鲁格曼就开放经济下的政策选择问题所提出的,其含义是:本国货币政策的独立性,汇率的稳定性,资本的完全流动性不能同时实现,最多只能同时满足两个目标,而放弃另外一个目标.根据蒙代尔的三元悖论,一国的经济目标有三种:1、各国货币政策的独立性;2、汇率的稳定性;3、资本的完全流动性. 这三者,一国只能三选其二,而不可能三者兼得.例如,在1944年至1973年的“布雷顿森林体系”中,各国“货币政策的独立性”和“汇率的稳定性”得到实现,但“资本流动”受到严格限制.而1973年以后,“货币政策独立性”和“资本自由流动”得以实现,但“汇率稳定”不复存在.“永恒的三角形”的妙处,在于它提供了一个一目了然地划分国际经济体系各形态的方法.
根据三元悖论,在资本流动,货币政策的有效性和汇率制度三者之间只能进行以下三种选择:
(1)保持本国货币政策的独立性和资本的完全流动性,必须牺牲汇率的稳定性,实行浮动汇率制.这是由于在资本完全流动条件下,频繁出入的国内外资金带来了国际收支状况的不稳定,如果本国的货币当局部进行干预,亦即保持货币政策的独立性,那么本币汇率必然会随着资金供求的变化而频繁的波动.利用汇率调节将汇率调整到真实反映经济现实的水平,可以改善进出口收支,影响国际资本流动.虽然汇率调节本身具有缺陷,但实行汇率浮动确实较好的解决了“三难选择”.但对于发生金融危机的国家来说,特别是发展中国家,信心危机的存在会大大削弱汇率调节的作用,甚至起到恶化危机的作用.当汇率调节不能奏效时,为了稳定局势,政府的最后选择是实行资本管制.
(2)保持本国货币政策的独立性和汇率稳定,必须牺牲资本的完全流动性,实行资本管制.在金融危机的严重冲击下,在汇率贬值无效的情况下,唯一的选择是实行资本管制,实际上是政府以牺牲资本的完全流动性来维护汇率的稳定性和货币政策的独立性.大多数经济不发达的国家,比如中国,就是实行的这种政策组合.这一方面是由于这些国家需要相对稳定的汇率制度来维护对外经济的稳定,另一方面是由于他们的监管能力较弱,无法对自由流动的资本进行有效的管理.
(3)维持资本的完全流动性和汇率的稳定性,必须放弃本国货币政策的独立性.根据蒙代尔-弗莱明模型,资本完全流动时,在固定汇率制度下,本国货币政策的任何变动都将被所引致的资本流动的变化而抵消其效果,本国货币丧失自主性.在这种情况下,本国或者参加货币联盟,或者更为严格地实行货币局制度,基本上很难根据本国经济情况来实施独立的货币政策对经济进行调整,最多是在发生投机冲击时,短期内被动地调整本国利率以维护固定汇率.可见,为实现资本的完全流动与汇率的稳定,本国经济将会付出放弃货币政策的巨大代价.
The Mundell-Fleming model is an economic model first set forth by Robert Mundell and Marcus Fleming. The model is an extension of the IS-LM model. Whereas IS-LM deals with economy under autarky, the Mundell-Fleming model tries to describe a small open economy.
Typically, the Mundell-Fleming model portrays the relationship between the nominal exchange rate and the economy output (unlike the relationship between interest rate and the output in the IS-LM model) in the short run. The Mundell-Fleming model has been used to argue that an economy cannot simultaneously maintain a fixed exchange rate, free capital movement, and an independent monetary policy. This principle is frequently called "the Unholy Trinity," the "Irreconcilable Trinity," the "Inconsistent trinity" or the Mundell-Fleming "trilemma."
Under flexible exchange rate regime
We speak of a system of flexible exchange rates when governments (or central banks) allow the exchange rate to be determined by market forces alone.
Typically this means governments (or central banks) announce an interest rate target which they are prepared to buy or sell any amount of domestic currency to maintain.
[edit] Changes in money supply
An increase in money supply will shift the LM curve to the right. This directly reduces the local interest rate and in turn forces the local interest rate lower than the global interest rate. This depreciates the exchange rate of local currency through capital outflow. The depreciation makes local goods cheaper compared to foreign goods and increases export and decreases import. Hence, net export is increased. Increased net export leads to the shifting of the IS curve to the right to the point where the local interest rate will equalize with the global rate. This increases the overall income in the local economy.
A decrease in money supply will cause the exact opposite of the process.
[edit] Changes in government spending
An increase in government expenditure shifts the IS curve to the right. The shift will cause the local interest rate to go above the global rate. The increase in local interest will cause capital inflow and the inflow will make the local currency stronger compared to foreign currencies. Strong exchange rate also makes foreign goods cheaper compared to local goods. This encourages greater import and discourages export and hence, lower net export. As a result, the IS will return to its original location where the local interest rate is equal to the global interest rate. The level of income of the local economy stays the same. The LM curve is not at all affected.
A decrease in government expenditure will reverse the process.
[edit] Changes in global interest rate
An increase in the global interest rate will cause an upward pressure on the local interest rate. The pressure will subside as the local rate closes in on the global rate. When a positive differential between the global and the local rate occurs, holding the LMB curve constant, capital will flow out of the local economy. This depreciates the local currency and helps boost net export. Increasing net export shifts the IS to the right. This shift will continue to the right until the local interest rate becomes as high as the global rate.
A decrease in global interest rate will cause the reverse to occur.
[edit] Under fixed exchange rate regime
We speak of a system of fixed exchange rates when governments (or central banks) announce an exchange rate (the parity rate) at which they are prepared to buy or sell any amount of domestic currency.
[edit] Changes in money supply
Under the fixed exchange rate system, the local central bank or any monetary authority will only change the money supply in order to maintain a level of exchange rate. If there is a pressure to appreciate the exchange rate, the local authority will increase its foreign reserve by purchasing foreign currencies with the local currency. This will return the exchange rate to its previous level. When there is a depreciation pressure, the authority will purchase its own currency in the market with its foreign reserve to return the currency to its pre-pressure state.
A revaluation occurs when there is a permanent increase in exchange rate and hence, decrease in money supply. Devaluation is the exact opposite of revaluation.
[edit] Changes in government expenditure
Increased government expenditure shifts the IS curve to the right. The shift encourages the interest rate to go up and hence, appreciation of the exchange rate. However, the exchange rate is controlled by the local monetary authority in the framework of a fixed system. In order to maintain the exchange and alleviate the pressure on the exchange rate, the monetary authority will purchase foreign currencies with local currencies until the pressure is gone i.e. back to the original level. Such action shifts the LM curve in tandem with the direction of the IS shift. This action increases the local currency supply in the market and lowers the exchange rate — or rather, return the rate back to its original state. In the end, the exchange rate stays the same but the general income in the economy increases.
The reverse is true when government expenditure decreases.
[edit] Changes in global interest rate
To maintain the fixed exchange rate, the central bank must offset the capital flows (in or out) which are caused by the change of the global interest rate to the domestic rate. The central bank must restore the situation where the real domestic interest rate is equal to the real global interest rate to stop net capital flows from changing the exchange rate.
If the global interest rate increases above the domestic rate, capital will flow out to take advantage of this opportunity. This would depreciate the home currency, so the central bank must buy the home currency and sell foreign currency reserves to offset this outflow. This decrease in the money supply shifts the LM curve to the left until the domestic interest rate is the global interest rate.
If the global interest rate declines below the domestic rate, the opposite occurs. Money flows in, the home currency would appreciate, so the central bank must offset this by increasing the money supply (sell domestic currency, buy foreign), the LM curve shifts right, and the domestic interest rate becomes the global interest rate.
[edit] Differences from IS-LM
It is worth noting that some of the result from this model differs from the IS-LM because of the open economy assumption. Result for large open economy on the other hand falls within the result predicted by the IS-LM and the Mundell-Fleming models. The reason for such result is because a large open economy has both the characteristics of an autarky and a small open economy.
In the IS-LM, interest rate will be the key component in making both the money market and the good market in equilibrium. Under the Mundell-Fleming framework of small economy, interest rate is fixed and equilibrium in both market can only be achieved by a change of nominal exchange rate.
[edit] Example
A much simplified version of the Mundell-Fleming model can be illustrated by a small open economy, in which the domestic interest rate is exogenously predetermined by the world interest rate (r=r*).
Consider an exogenous increase in government expenditure, the IS curve will shift upward, with LM curve intact, causing the interest rate and the output to rise (partial crowding out effect) under the IS-LM model.
Nevertheless, as interest rate is predetermined in a small open economy, the LM* curve (of exchange rate and output) is vertical, which means there is exactly one output that can make the money market in the equilibrium under that interest rate. Even though the IS* curve still shift up, it will result in a higher exchange rate and same level of output (complete crowding out effect, which is different in the IS-LM model).
The example above makes an implicit assumption of flexible exchange rate. The Mundell-Fleming model can have completely different implications under different exchange rate regimes. For instance, under a fixed exchange rate system, with perfect capital mobility, monetary policy becomes ineffective. An expansionary monetary policy resulting in an outward shift of the LM curve would in turn make capital flow out of the economy. The central bank under a fixed exchange rate system would have to intervene by selling foreign money in exchange for domestic money to depreciate the foreign currency and appreciate the domestic currency. Selling foreign money and receiving domestic money would reduce real balances in the economy, until the LM curve shifts back to the left, and the interest rates come back to the world rate of interest i*.